Battle of Changban

The Battle of Changban occurred in 208 AD during the war between Cao Cao and Liu Bei. Cao Cao's larger army failed to corner and destroy Liu Bei's smaller army and large following of civilians at Changban, with Liu Bei fleeing to Jiangling. While Cao Cao won the field, Liu Bei escaped to Wu, where he allied with Sun Quan.

Background
In 207 AD, Cao Cao unified northern China with his defeat of Yuan Shao's sons, and he made arrangements to campaign against Jing Province ruler Liu Biao. However, Liu Biao's general Liu Bei repelled Xiahou Dun's invasion, and, by the time that Cao Cao himself was invading Jing Province, Liu Biao died of illness. Liu Biao's advisers Fu Xun and Kuai Yue convinced Liu Cong to surrender to Cao Cao, who acquired the entire province and much of Liu Biao's former army. Liu Bei decided to retreat with his army rather than attack Liu Cong or be defeated by Cao Cao, and, as he passed Xiangyang, he found himself joined by 100,000 civilians, who admired the popular and benevolent Liu Bei.

Battle
Cao Cao gave chase to Liu Bei with an army of 5,000 cavalry, and the two armies met in battle at Changban between the Han and Yangtze Rivers. Liu Bei continued to march with the peasants, while Zhang Fei led the rearguard. Zhang Fei stood alone at a bridge and broke the other bridges down, blocking Cao Cao's advance. The fearsome Zhang Fei held off several attacks from Cao Cao's forces, and he bought time for Liu Bei's escape. In the meantime, Zhao Yun charged behind Cao Cao's lines to rescue Liu Bei's wife Lady Gan and their infant son, Adou, and he fought his way back through Cao Cao's forces to deliver Liu Bei's son and wife to him; he slew Xiahou En in the process.

Fighting retreat
The combined Liu Bei army proceeded to continue its retreat, covered by the strategist Zhuge Liang's tactics. He used a fire attack to hold off Cao Cao's advancing forces, and Liu Bei continued to retreat. However, Xiahou Dun and Xu Huang arrived with more reinforcements for Cao Cao's army, causing Zhao Yun to rush back to hold off Cao Cao's reinforcements as they advanced from the north. As Zhao Yun held off Cao Cao's reinforcements, Guan Yu and a fleet of ships arrived to transport Liu Bei to safety, and Liu Qi later arrived with reinforcements for Liu Bei's army. Shortly after, Jia Xu arrived with reinforcements for Cao Cao, this time emerging from the southeast, right behind Liu Bei's army. Zhao Yun rushed south and routed Jia Xu's force, while also capturing an attack base that Jia Xu's men had created. Shortly after, Cao Cao himself arrived on the battlefield with the main army. However, he was too late to stop Liu Bei's escape to Guan Yu's ships, and Liu Bei was able to escape and link up with Sun Quan's armies.